The present invention relates to a disk drive on which a magnetic disk (hereinafter, referred merely to as a disk) can be loaded and rotation driven for the purpose of recording and reproducing information, the disk comprising a flexible disk housed in a casing to magnetically record and reproduce the information. More particularly, the present invention relates to an improvement of a disk loading and unloading mechanism.
Disk drives of the type described typically receive the disk, as a received disk, for the purpose of rotation driving the received disk and recording/reproducing the information. The received disk is held by a disk table. A magnetic head for information recording/reproducing (hereinafter, referred merely to as a head) is in contact with the received disk on the disk table. The head records and reproduces the information on and from the received disk. The received disk is ejected out of the disk drive after completion of the recording and/or reproducing of the information. To this end, typical disk drives have a disk loading and unloading mechanism.
Referring to FIGS. 1 and 2, the disk loading and unloading mechanism oF a conventional disk drive is shown. In FIG. 1, the disk drive comprises a main chassis 110, an eject plate 120, and a disk holder 130, which are all made by pressing a sheet metal.
The main chassis 110 has a main base section 111, opposing side wall sections 112 and 113, a back end wall section 114, a pair of support portions 115 and another pair of support portions 116. The side wall sections 112 and 113 extend upward from the both side edges of the main base section 111. Likewise, the back end wall section 114 extends upward from the rear edge of the main base section 111. Each of the support portions 115 and 116 have shoulder portions 115a and 116a, respectively. The shoulder portion is formed by means of cutting and raising a portion of the main base section 111 with a notch formed in a part of the cut and raised portion.
A magnetic disk table 140 and a carriage mechanism 150 are mounted on the main base section 111 in the direction along the side wall sections of the main chassis 110. The magnetic disk table 140 is provided for rotation driving a disk while holding it. The carriage mechanism 150 has an upper head and a lower head which are driven by the carriage mechanism 150 on the upper (top) surface and the lower (back) surface, respectively, of the disk. A motor 160 is mounted on the back end wall section 114. The motor 160 has a rotation shaft with a helical thread thereto. The motor 160 is arranged such that the rotation shaft extends in the direction along the side wall sections of the main chassis 110.
The magnetic disk table 140 is directly connected to and rotation driven by a rotor assembly of a motor (not shown) for use in rotating the disk. The rotor assembly is provided beneath the main chassis 110. The carriage mechanism 150 has an engaging member that engages with the helical thread in the rotation shaft of the motor 160. In addition, the carriage mechanism 150 has a support frame through which a guide shaft passes. The guide shaft is fixedly secured to the main base section 111.
The engaging member of the carriage mechanism 150 moves in the direction along the side wall sections of the main chassis 110 in response to the rotation of the motor 160. This in turn moves linearly the carriage mechanism in the direction along the side wall sections of the main chassis 110, that is, the radial direction of the disk.
The eject plate 120 comprises a main base section 121, side wall sections 122 and 123 and a button mounting projection 124. The main base section 121 has a generally U shape. The side wall sections 122 and 123 extend vertically from the both side edges of the main base section 121. The button mounting projection 124 extends forward from the front edge of the main base section 121. The eject plate 120 is also provided with a pair of notches 125 and a pair of holes 126. The notches 125 and the holes 126 are formed at the position corresponding to the support portions 115 and 116, respectively, of the main chassis 110. A pair of guide grooves 127 are formed in the side wall sections 123 and 124. A bent projection 128 is provided at the rear end of the side wall section 122, projecting outward therefrom.
The guide grooves 127 each include a horizontal portion and a tilt portion. A linear gear 129 is provided in the rear portion of the main base section 121 which the linear gear is adapted to engage with a damper gear (not shown) on the main chassis 110.
The eject plate 120 is assembled with the main chassis 110 with the support portions 115 and 116 on the main chassis 110 passed through the notches 125 and the holes 126, respectively. In particular, the edges of the notches 125 and the holes 126 in the main base section 121 are supported by the shoulder portions 115a and 116a of the support portions 115 and 116, respectively. Consequently, the eject plate 120 is slidable back and forth with respect to the main chassis 110. However, the eject plate 120 is allowed to be moved only slightly in the up and down directions and the right and left directions. This is because the support portions 115 and 116 restrict the movement of the edges of the notches 125 and the holes 126 in the direction other than forward and backward. As shown in FIG. 2, the bent projection 128 on the side wall section 122 is opposed to the inner surface of the side wall section 112 on the main chassis 110 at a small gap from the inner surface.
As described above, the main base section 121 has the generally U shape. Therefore, the eject plate 120 is slidable without interrupting the operation of the disk table 140 and the carriage mechanism 150.
The disk holder 130 has a main base section 131, opposing side wall sections 132 and 133, and four protrusions 134. The four protrusions 134 are projected outward from the side wall sections. The main base section 131 has a notch 130a that is not affected by the movement of the upper head of the carriage mechanism 150. The side wall sections 132 and 133 extend downward from the both side edges of the main base section 131. The free end of the side wall sections 132 and 133 are bent inward to hold the disk. The protrusions 134 are located at the position corresponding to the guide grooves 127 in the eject plate 120.
The disk holder 130 is assembled with the eject plate 120 already assembled with the main chassis 110. During assembly, the protrusions 134 are passed through the respective guide grooves 127. The disk drive is thus configured. Alternatively, the disk drive may be assembled by means of first assembling the disk holder 130 with the eject plate 120 and then assembling the resultant combination with the main chassis 110. The disk drive of the type described is disclosed in, for example, Japanese Patent Laid-open No. 9-91826.
The disk drive disclosed herein has other features in addition to those described above. For example, a projection (not shown) mounted on the disk holder 130 is passed through a hole (not shown) formed in the main chassis 110. With this configuration the disk holder 130 is slidable upward and downward relative to the main chassis 110 but is restricted in movement in the back and forth directions and the right and left directions. More specifically, the disk holder 130 is slidable upward and downward in cooperation with the back-and-forth movement of the eject plate 120, depending on the configuration of the guide grooves 127 formed in the eject plate 120. A tension spring (not shown) is provided between the eject plate 120 and the disk holder 130. The tension spring pulls the eject plate 120 in the forward direction relative to the main chassis 110. The eject plate 120 is locked with a locking mechanism (not shown) at a position in a rear portion of the main chassis 110 where the eject plate 120 is located against the pulling force of the tension spring. In addition, there is an eject mechanism (not shown) provided that acts on the disk in cooperation with the locking mechanism, in order to eject the disk out of the disk drive. An eject button 170 is mounted on the button mounting projection 124 to allow an operator to eject the disk. The above-mentioned features are disclosed in, for example, Japanese Patent Laid-open No. 9-91943.
Next, operation of loading and unloading the disk is described. In the absence of the disk, the eject plate 120 is at a retracted position with being locked by the locking mechanism (the tension spring is pulled). At this point, the disk holder 130 is located at an upper portion in association with the guide grooves 127 and the protrusions 134. When the disk is loaded onto the disk holder 130, the lock mechanism is released. Consequently, the tension spring causes the eject plate 120 to move forward when the spring returns to its original shape. This lowers the disk holder 130 and completes the disk loading operation. Thus the disk is now ready to be accessed to record and/or reproduce the information.
Depression of the button 170 in this state causes movement of the eject plate 120 in the backward direction. The eject plate 120 is then locked again by the locking mechanism and is kept at that retracted position (the tension spring is pulled or expanded). The disk holder 130 is located upward and the eject mechanism acts on the disk in cooperation with the lock mechanism to eject it out of the disk holder.
As apparent from the above, the track of the sliding motion of the eject plate 120 is defined by the configuration of the shoulders 115a and 116a of the support portions 115 and 116, respectively. The shoulder portions 115a and 116a each have a cut surface which is a rough edge surface, so that a problem may arise in slidability thereon. Taking this into consideration, grease is applied to a contact surface between the eject plate 120 and the shoulders 115a and 116a. However, there is a disadvantage that the grease may migrate to the inner surface of the eject plate 120 and in turn to the disk.